Snatch block for cranes

ABSTRACT

A versatile snatch block arranged for carrying a large hoisting hook and for being suspended in any of several different manners from the hoisting cable of a crane is made up of a pair of side plates, sheave plates, liner plates, spacers and pins. The pins are for clamping the plates and spacers together and the block is suspended from the hoisting cable through the use of one of the pins while the other pin serves to support the large hoisting hook.

United States Patent Koster Nov. 4, 1975 SNATCH BLOCK FOR CRANES 1,730,433 10/1929 MacDonald 254/192 3,179,376 4 1965 B tt 254 192 [75] Invent: Aloys'us Roster Los Angeles 3,652,116 311972 P3113 294/82 R Calif.

[73] Assignee: SSP Truck Equipment, Inc., Primary Examiner-James B. Marbert V Paramount, Calif. Assistant Examiner-Johnny D. Cherry [22] Filed: Dec. 3 1973 Attorney, Agent, or Firm-Huebner & Worrel 21 Appl. No.: 421,036 [57] ABSTRACT A versatile snatch block arranged for carrying a large R; hoisting and for being Suspended in y of C l/ 866D l/36 eral different manners from the hoisting cable of a 1 d 0 Seal ch 294/78 82 83 crane is made up of a pair of side plates, sheave plates,

54/192496 188 liner plates, spacers and pins. The pins are for clamping the plates and spacers together and the block is [56] Referenc cued suspended from the hoisting cable through the use of UNITED STATES PATENTS one of the pins while the other pin serves to support 390,341 10 1888 Brown 254 192 the large hoisting hook. 1,713,586 5/1929 Wright.... 294/82 R X 1,713,587 5/1929 Wright 254/192 8 Clams, 10 Drawing Figures US. Patent Nov. 4, 1975 Sheet 1 of5 3,917,334

US. Patent Nov. 4, 1975 Sheet 2 of5 3,917,334

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U8. Patent Nov. 4, 1975 Sheet 3 of 5 US. Patent Nov. 4, 1975 Sheet4 of5 3,917,334

Sheet 5 of 5 US. Patent Nov. 4, 1975 SNATCH BLOCK FOR CRANES BACKGROUND OF THE INVENTION The present invention relates to cranes and more particularly to a snatch block for use therewith.

The term snatch block as used herein refers to a hoisting block arranged to carry a hoisting hook and for suspension from the hoisting cable of a crane. The snatch block by its weight will additionally assist in establishing a proper reeving of the cable as a telescoping crane is retracted or extended. In other words it assures proper cable tension by its weight and mass.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved versatile snatch block arranged for carrying a relatively large hoisting hook and maintaining it in a substantially vertical orientation and characterized by being capable of being suspended from a hoisting cable in any of several different manners.

In accomplishing these and other objects, there is provided a snatch block which is illustrated suspended from the hoisting cable of a crane firstly by being pinned through a wire rope thimble, secondly by being hooked on a relatively small hoisting hook, and thirdly by use of a sheave around which the hoisting cable is reeved.

Additional objects of the present invention reside in the specific construction of the snatch block shown in the drawings and described hereinafter in connection therewith.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a portable crane having disposed on the end of its hoisting cable a snatch block according to the present invention.

FIG. 2 is a side elevation view of the snatch block shown in FIG. 1 illustrated connected on the end of a hoisting cable by being pinned through a wire rope thimble.

FIG. 3 is a side view taken along the line 33 of FIG. 2.

FIG. 4 is a side elevation view of one of the side plates of the snatch block of FIG. 2.

FIG. 5 is a side elevation view of one of the sheave plates of the snatch block of FIG. 2.

FIG. 6 is a side elevation view of one of the liner plates of the snatch block of FIG. 2.

FIG. 7 is a side elevation view of one of the spacers of the snatch block of FIG. 2.

FIG. 8 is a side elevation view of the snatch block of FIG. 2 illustrated suspended from a relatively small sized hook on the end of a hoisting cable.

FIG. 9 is a side elevation view of the snatch block of FIG. 2 illustrated suspended on the hoisting cable of FIG. 1 by means of a sheave pinned in the snatch block around which the cable is reeved.

FIG. 10 is a view taken along the line 10-10 of FIG. 9.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 2 made of wire rope and a snatch block 12 is illustrated suspended from the end of the cable 11.

The construction of the snatch block 12 is shown in detail in FIGS. 2-7. The block 12 is made up of a pair of similar side plates 13, sheave plates 14, liner plates 15 and spacers 16. One of the plates 13, 14, 15 and spacers 16 are shown, respectively, in FIGS. 4, 5, 6 and 7, and these parts are preferably made of steel.

The side plates 13, sheave plates 14 and liner plates 15 all have the same width, are preferably rounded on their bottom edges and have horizontally extending top edges. The side and bottom edges of the side plates 13 are chamfered to form a scarf 20 on their outer faces. The length of the side plates 13 from bottom to top is preferably slightly greater than half the length of sheave plates 14. The liner plates 15 are U-shaped and their length is slightly less than the length of the sheave plates 14. The spacers 16 are substantially triangularly shaped with their longest edge shaped to conform with the edge portions of the side plates 13 extending from the side plate top approximately two-thirds of the way down its side.

In one snatch block constructed in accordance with the present invention, the side plates were 2 inches thick, 9 inches wide and 7% inches long; the sheave plates were 1 inch thick, 9 inches wide and 13% inches long; the liner plates were one-half inch thick, 9 inches wide and 13 /2 inches long; and the spacer plates were 1% inches thick, 2 /8 inches wide and 6 /8 inches long. Further, the U-shaped cavity defined by the liner plate 15 and identified by the numeral 21 in FIG. 6 was 5 inches wide and 9 /2 inches long. The weight of the aforedescribed snatch block approximated pounds. With such weight on the hoist cable 11 tension can be maintained during the cable reeving of a telescoping crane 10 when said crane is being extended or retracted. Such smooth telescoping movement is assured.

As shown in FIG. 3, the plates 13, 14 and 15 have aligned equal sized horizontally extending holes formed through their lower ends which define a bore 22. A block pin 23 is shown inserted through the bore 22 and the spacers 16 are positioned between the liner plates 15 in the disposition shown in dashed lines in FIG. 2. The block pin 23 has a fixed head 24 on one end and a removable head 25 secured on its other end by a conventional lock wire cap screw arrangement 26.

As shown in FIG. 3, with the vertical edges of the plates 13, 14 and 15 aligned and the pin 23 in place with its head 25 secured tightly thereon, the bottom edges of the plates l3, 14 are aligned and the lower edge of the plates 15 is positioned slightly above the lower edges of the plates 13, 14. Thereby, a lower cavity or recess 27 is defined centrally within the block 12 for receiving the upper end 30 of the shank of the conventional closed swivel bail safety hook 31 shown in FIG. 3. The closed bail 32 of the hoisting hook 31 is positioned within the space between the liner plates 15. The width of this space is determined by the width of the spacers 16 which hold the liner plates 15 apart. The safety hook 31 has pin 33 which may be depressed to lock or unlock the hooks safety gate 34.

A second horizontally extending bore 40 as defined in the snatch block 12 approximately halfway up its length by forming horizontally extending holes through the plates 13 and 14. It is noted that this bore 40 as well as the bore 22 extends through the vertical centerline of the block 12.

In FIG. 3, an appropriately dimensioned pin 41 of the same type as pin 23 is secured in the bore 40 to extend through a conventional wire rope thimble 42 swaged at point 43 on the hoisting cable 11. Thus, the snatch block 12 is shown carrying a downwardly depending hoisting hook 31 and suspended from the hoisting cable 11 by being pinned through the wire rope thimble 42.

It is noted that in order to insure that the spacers 16 do not drop from the position in which they are clamped between the liner plates 15 that pins 44, shown in FIG. 2, may be pinned through the block 12. It is also noted that in the snatch block earlier mentioned constructed in accordance with the present invention that the pins 23 and 41 were, respectively, approximately 2 inches and 1 /1 inches in diameter.

In FIG. 8, the snatch block 12 is shown suspended from a small hook 50 swaged at point 51 on the hoisting cable 11. The hook 50 is hooked around the upper block pin 41. Thus, the snatch block 12 is illustrated being employed to attach a large sized hoisting hook, i.e. the hook 31, on the end of a cable 11 on which a standard small sized hook is swaged, i.e. the hook 50, without requiring the removal of the small hook 50.

Referring to FIGS. 9 and 10, a sheave or pulley 60 is shown rotatably mounted in the U-shaped cavity 21 defined by the liner plates 15. The sheave 60 is shown mounted on sheave pin 61. The pin 61 is of the same type as the above-described pins 23 and 41 and is appropriately dimensioned for being secured in the horizontally extending bore 62 defined through the upper portions of the sheave plates 14. It is pointed out that in order to place the sheave 60 in place the pin 23 is removed. Also the bore 62 is preferably located a distance from the top of the plates 14 along their centerline at least as great as the radius of the sheave 60 so that the sheave 60 does not stick out above the block 12.

In FIG. 9, the snatch block 12 is shown suspended on the hoisting cable 11 by reeving the line 11 around the sheave 60 and hooking the small hook 50 swaged on its end to an anchor point 63 on the crane. Thereby, the snatch block 12 is supported by cable extending from two points on the crane 10. Further, since the cable 11 may be reeved around the sheave 60 prior to pinning it in the block 12, there is no need to remove the small book 50in order to suspend on the cable 11 the snatch.

block 12. Thereby, the large hoisting hook 31 may be suspended on the cable 11 without requiring the removal of the small hook 50 swaged on the cable.

It is noted that the side plates 13 of the block 12, the U-shape of the liner plates 15, and the location of the spacers 16 all function as weights which locate the center of gravity of the block 12 somewhere in its lower half. Thus, the block 12 even when unloaded will hang with its hook 31 disposed downwardly. As a consequence, the block 12 eliminates the need of clamping a separate weight or headache pill on a hoisting cable as has heretofore been necessary to prevent hoisting hooks from tilting from a vertical orientation when unloaded due to the tendency of the hoisting cable to coil. Such tilted hooks are undesirable since it is more difiicult to hook them to a load to be hoisted.

While the preferred construction of the block 12 has been described above wherein it is formed from a series of plates, optional construction could be accomplished by casting the block 12 in two mateable halves and securing the halves to form the completed block.

4 Although the invention has been herein shown and described in what is conceived tobe the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of this bores defined therethrough which extend through said vertical centerline, a first one of said bores being located adjacent the lower end of said block structure, a second one of said bores being located approximately midway between the upper and lower ends of said block structure, a third one of said bores being located in the upper half of said block structure; said structure defining a downwardly opening centrally located cavity in its lower end for receiving.

the bail of a swivel type hoisting hook, said first bore traversing said first cavity whereby a pin may be inserted in said first bore through the bail of a hoisting hook positioned in said first cavity to secure a hoisting hook in a depending position from the lower end of said block structure;

said structure defining an upwardly opening centrally located cavity which extends upwardly from a selected point in the lower half of said block structure, said second and third bores traversing at least portions of said second cavity whereby a pin may be inserted in either said second or third bores for use in suspending the upper end of said block structure from a hoisting cable extending downwardly into said second cavity;

said block structure being comprised of a plurality of plates of predetermined thicknesses and weights held apart by spacer means, said plates being clampable together by pins of appropriate length pinned through selected ones of said bores;

said plurality of plates being made up of two similar groups which are held apart by said spacer means;

said spacer means being two similar spacers for positioning adjacent opposite side edges of said plates; and

each of said plate groups being comprised of a side plate, sheave plate and liner plate, said side plate being for positioning outermost, said liner plate being for positioning innermost, said sheave plate being for positioning between said side and liner plates,

said, side plates being approximately one-half as long as said sheave plates, said liner plates being slightly shorter than said sheave plates, and said plates being assembled with the lower ends of said side and sheave plates being flush and the lower ends of said liner plates being positioned slightly above the lower ends of said sheave plates.

2. The invention defined in claim 1, wherein said liner plates define an upwardly openingsubstantially U-shape dimensioned for receiving a sheave rotatably mounted on a pin inserted in said third bore.

3. The invention defined in claim 2, wherein:

said first bore is defined through said side, sheave and liner plates;

,said second bore is defined through said side and sheave plates; and

said third bore is defined through said sheave plates.

4. The invention defined in claim 3, wherein said block structure is weighted to have its center of gravity located in its lower half to hang and thereby maintain a hoisting hook depending therefrom in a vertical orientation.

5. The invention defined in claim 4, in combination with:

a closed bail swivel type hoisting hook;

a first pin for insertion and pinning in said first bore to clamp said plates and spacers together; and

a second pin for insertion and pinning in either said second or third bores to also clamp said plates and spacers together. 6. The invention defined in claim 5, in combination with a sheave and wherein said second pin is for insertion and pinning in said third bore. 7. A snatch block, comprising: block structure having upper and lower ends and a vertical centerline, said structure having a plurality of horizontally extending vertically spaced apart bores defined therethrough which extend through said vertical centerline, a first one of said bores being located adjacent the lower end of said block structure, a second one of said bores being located above the first of said bores; said structure defining downwardly opening centrally located cavity in its lower end for receiving the bail of a hoisting hook, said first bore traversing said first cavity whereby a pin may be inserted in said first bore through the bail of a hoisting hook positioned in said first cavity to secure a hoisting hook in a depending position from the lower end of said block structure; said structure defining an upwardly opening centrally located cavity which extends upwardly from a selected point in the lower half of said block structure, said second bore traversing said second cavity whereby a pin may be inserted in said second bore for use in suspending the upper end of said block structure from a hoisting cable extending downwardly into said second cavity; said block structure being comprised of a plurality of plates of predetermined thicknesses and weights held apart by spacer means, said plates being clampable together by pins of appropriate length pinned through selected ones of said bores; said plurality of plates being made up of two similar groups which are held apart by said spacer means;

said spacer means being two similar spacers for positioning adjacent opposite side edges of said plates; and

each of said plate groups being comprised of a side plate, sheave plate and liner plate, said side plate being for positioning outermost, said liner plate being for positioning innermost, said sheave plate being for positioning between said side and liner plates;

said side plates being approximately one-half as long as said sheave plates, said liner plates are slightly shorter than said sheave plates, and said plates are assembled with the lower ends of said side and sheave plates flush and the lower ends of said liner plates positioned slightly above the lower ends of said sheave plates;

whereby said block is weighted to have its center of gravity located in its lower half to hang and thereby maintain a hoisting hook depending therefrom in a vertical orientation.

8. A snatch block and hoisting hook comprising:

block structure having upper and lower ends and a vertical centerline, said structure having a plurality of horizontally extending vertically spaced apart bores defined therethrough which extend through said vertical centerline, a first one of said bores being located adjacent the lower end of said block structure, a second one of said bores being located above the first of said bores;

said structure defining a downwardly opening centrally located cavity in its lower end for receiving the bail of a hoisting hook, said first bore traversing said first cavity whereby a pin may be inserted in said first bore through the bail of a hoisting hook positioned in said first cavity to secure a hoisting hook in a depending position from the lower end of said block structure;

. said structure defining an upwardly opening centrally located cavity which extends upwardly from a selected point in the lower half of said block structure, said second bore traversing said second cavity whereby a pin may be inserted in said second bore for use in suspending the upper end of said block structure from a hoisting cable extending downwardly into said second cavity;

said block being weighted to have its center of gravity located in its lower half to hang and thereby maintain a hoisting hook depending therefrom in a vertical orientation;

said second bore being located approximately midway between the upper and lower end of said block structure;

a third one of said bores being located in the upper half of said block structure above said second bore, whereby a pin may be inserted in either said second or third bores for use in suspending the upper end of said block structure from a hoisting cable extending downwardly into said second cavity;

said second cavity being dimensioned for receiving a lower portion of a sheave rotatably mounted on a pin inserted in said third bore;

a closed bail swivel type hoisting hook, said closed bail being positioned in said first cavity;

a first pin inserted in said first bore securing said hoisting hook in said first cavity;

a sheave having its lower portion in said second cavity; and

a second pin inserted in said third bore supporting said sheave in said block. 

1. A snatch block, comprising: block structure having upper and lower ends and a vertical centerline, said structure having a plurality of horizontally extending vertically spaced apart bores defined therethrough which extend through said vertical centerline, a first one of said bores being located adjacent the lower end of said block structure, a second one of said bores being located approximately midway between the upper and lower ends of said block structure, a third one of said bores being locateD in the upper half of said block structure; said structure defining a downwardly opening centrally located cavity in its lower end for receiving the bail of a swivel type hoisting hook, said first bore traversing said first cavity whereby a pin may be inserted in said first bore through the bail of a hoisting hook positioned in said first cavity to secure a hoisting hook in a depending position from the lower end of said block structure; said structure defining an upwardly opening centrally located cavity which extends upwardly from a selected point in the lower half of said block structure, said second and third bores traversing at least portions of said second cavity whereby a pin may be inserted in either said second or third bores for use in suspending the upper end of said block structure from a hoisting cable extending downwardly into said second cavity; said block structure being comprised of a plurality of plates of predetermined thicknesses and weights held apart by spacer means, said plates being clampable together by pins of appropriate length pinned through selected ones of said bores; said plurality of plates being made up of two similar groups which are held apart by said spacer means; said spacer means being two similar spacers for positioning adjacent opposite side edges of said plates; and each of said plate groups being comprised of a side plate, sheave plate and liner plate, said side plate being for positioning outermost, said liner plate being for positioning innermost, said sheave plate being for positioning between said side and liner plates, said side plates being approximately one-half as long as said sheave plates, said liner plates being slightly shorter than said sheave plates, and said plates being assembled with the lower ends of said side and sheave plates being flush and the lower ends of said liner plates being positioned slightly above the lower ends of said sheave plates.
 2. The invention defined in claim 1, wherein said liner plates define an upwardly opening substantially U-shape dimensioned for receiving a sheave rotatably mounted on a pin inserted in said third bore.
 3. The invention defined in claim 2, wherein: said first bore is defined through said side, sheave and liner plates; said second bore is defined through said side and sheave plates; and said third bore is defined through said sheave plates.
 4. The invention defined in claim 3, wherein said block structure is weighted to have its center of gravity located in its lower half to hang and thereby maintain a hoisting hook depending therefrom in a vertical orientation.
 5. The invention defined in claim 4, in combination with: a closed bail swivel type hoisting hook; a first pin for insertion and pinning in said first bore to clamp said plates and spacers together; and a second pin for insertion and pinning in either said second or third bores to also clamp said plates and spacers together.
 6. The invention defined in claim 5, in combination with a sheave and wherein said second pin is for insertion and pinning in said third bore.
 7. A snatch block, comprising: block structure having upper and lower ends and a vertical centerline, said structure having a plurality of horizontally extending vertically spaced apart bores defined therethrough which extend through said vertical centerline, a first one of said bores being located adjacent the lower end of said block structure, a second one of said bores being located above the first of said bores; said structure defining downwardly opening centrally located cavity in its lower end for receiving the bail of a hoisting hook, said first bore traversing said first cavity whereby a pin may be inserted in said first bore through the bail of a hoisting hook positioned in said first cavity to secure a hoisting hook in a depending position from the lower end of said block structure; said structure defining an upwardly Opening centrally located cavity which extends upwardly from a selected point in the lower half of said block structure, said second bore traversing said second cavity whereby a pin may be inserted in said second bore for use in suspending the upper end of said block structure from a hoisting cable extending downwardly into said second cavity; said block structure being comprised of a plurality of plates of predetermined thicknesses and weights held apart by spacer means, said plates being clampable together by pins of appropriate length pinned through selected ones of said bores; said plurality of plates being made up of two similar groups which are held apart by said spacer means; said spacer means being two similar spacers for positioning adjacent opposite side edges of said plates; and each of said plate groups being comprised of a side plate, sheave plate and liner plate, said side plate being for positioning outermost, said liner plate being for positioning innermost, said sheave plate being for positioning between said side and liner plates; said side plates being approximately one-half as long as said sheave plates, said liner plates are slightly shorter than said sheave plates, and said plates are assembled with the lower ends of said side and sheave plates flush and the lower ends of said liner plates positioned slightly above the lower ends of said sheave plates; whereby said block is weighted to have its center of gravity located in its lower half to hang and thereby maintain a hoisting hook depending therefrom in a vertical orientation.
 8. A snatch block and hoisting hook comprising: block structure having upper and lower ends and a vertical centerline, said structure having a plurality of horizontally extending vertically spaced apart bores defined therethrough which extend through said vertical centerline, a first one of said bores being located adjacent the lower end of said block structure, a second one of said bores being located above the first of said bores; said structure defining a downwardly opening centrally located cavity in its lower end for receiving the bail of a hoisting hook, said first bore traversing said first cavity whereby a pin may be inserted in said first bore through the bail of a hoisting hook positioned in said first cavity to secure a hoisting hook in a depending position from the lower end of said block structure; said structure defining an upwardly opening centrally located cavity which extends upwardly from a selected point in the lower half of said block structure, said second bore traversing said second cavity whereby a pin may be inserted in said second bore for use in suspending the upper end of said block structure from a hoisting cable extending downwardly into said second cavity; said block being weighted to have its center of gravity located in its lower half to hang and thereby maintain a hoisting hook depending therefrom in a vertical orientation; said second bore being located approximately midway between the upper and lower end of said block structure; a third one of said bores being located in the upper half of said block structure above said second bore, whereby a pin may be inserted in either said second or third bores for use in suspending the upper end of said block structure from a hoisting cable extending downwardly into said second cavity; said second cavity being dimensioned for receiving a lower portion of a sheave rotatably mounted on a pin inserted in said third bore; a closed bail swivel type hoisting hook, said closed bail being positioned in said first cavity; a first pin inserted in said first bore securing said hoisting hook in said first cavity; a sheave having its lower portion in said second cavity; and a second pin inserted in said third bore supporting said sheave in said block. 